| 摘要 |
PROBLEM TO BE SOLVED: To provide a leakage detecting device capable of improving linearity of pulse signals corresponding to leakage input waveforms at a plus side and a minus side inputs and improving detecting accuracy. SOLUTION: The leakage detecting circuit outputs in phase leakage input waveforms in a normal-rotation input circuit 11 and reverse-phase waveforms in a reverse input circuit 12, and integration circuits 14, 15 input inphase and reverse-phase leakage input waveforms through a switch 13 to alternately charge and discharge in the integration circuits 14, 15, where they discharge during the period of not charging and charge during the period of not discharging. A VF conversion circuit 16 resets the integration circuits 14, 15 when the size of the output signal waveforms of the integration circuits reaches a given level and changes over the switch 13 through a switching circuit 17 to output pulse signals of frequencies in accordance with the leakage input waveforms. An arithmetic circuit 18 carries out an interruption operation from both judgment results of widths of leakage input waveforms from a zero-phase-sequence transformer 4 and integrated values of the pulse signals outputted from the VF conversion circuit 16. COPYRIGHT: (C)2004,JPO&NCIPI
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